1. Field of the Invention
The present invention relates to hydraulic couplers having a lever controlled intermediate valve in the coupler.
2. Prior Art
My U.S. Pat. No. 3,680,591, issued Aug. 1, 1972, for Unique Hydraulic Coupler, shows a cam controlled intermediate valve coupler assembly. In the above mentioned patent, an intermediate valve chamber is provided, and during operation, an external bleed is used to relieve pressure buildup in the chamber when necessary. As shown therein, the bleed is provided by permitting leakage to the exterior of the coupler past provided O rings when an intermediate valve assembly moves to a particular position.
The present device provides an intermediate chamber having a piston that will move slightly when controlled by a cam to relieve pressure in the interior valve chamber. The device is easily made from automatically produced parts, and avoids the possibility of visible external leakage.